What assumptions do savings group advocates and practitioners hold about how groups work, and are they justified? As NGOs promote ever more savings groups, they cite a list of benefits: access to funds for emergencies and investments, profits on savings, and strengthened social ties. At the same time, they generally follow a set of "golden rules": pay out annually, charge interest, target women. Yet, the benefits are only realized when a number of factors fall into place, and the rules don't always make sense in different contexts. Savvy NGOs, promoters and group members are already questioning these assumptions and adapting policies to better meet their needs; more could do so. In this paper, we question some pervasive assumptions about savings groups, providing counter-examples and lessons learned from our own experiences, those of practitioners in the field, and published literature.